Numerical Modeling in 3D of Rift Segmentation, Propagation, and Oblique Rifting: Control of Strain Weakening and Brittle Ductile Coupling

The work proposed here focuses on understanding the evolution and structural style of sedimentary basins and passive margins in 3 dimensions (3D) using state of the art computational modelling techniques. To date very few 3D models exist that follow the e volution of rifting to large deformation with sufficient resolution to resolve individual fault and shear zones. Here we propose to use state of the art finite element techniques developed over the last 3 years in collaboration with Dr Christopher Beaumon t (Geodynamics Group, Dalhousie University, Halifax, Canada) and Dr Jean Braun (Rennes University, France) that solve for viscous-plastic flows in 3 dimensions to model 3D features of continental rifting and passive margin formation that are so far not ve ry well understood. The project aims to understand three aspects of lithosphere extension and passive margins formation that are intimately related and which are inherently 3D in nature: 1) along axis segmentation and variation in structural style of ri ft basins and passive margins; 2) along axis rift propagation from well developed rift zones into un-extended continental lithosphere; and 3) occurrence of orthogonal extension versus transtensional extensional deformation. Insight into the 3D structural evolution of these systems is both a fundamental first order scientific problem but is also highly relevant for hydro-carbon exploration, as well as for understanding seismic hazard potential in these settings. Funding is requested for the support of a PhD student for three years and a post-doctoral fellow for three years. This funding will enable us to undertake the three closely related but distinct research projects proposed below.